SENAT
Report n° 117 (2007-2008) by M. Roland COURTEAU, Senator (for the parliament office for the evaluation of scientific and technological choices) - Appendix to the minutes of the 7 December 2007 session
Disponible au format Acrobat (21 Moctets)
b) No ocean basin is safe from tsunamis
In the Mediterranean , the collision between the African and Eurasian Plates makes this region particularly prone to earthquakes and tsunamis. The large tsunamis to have struck this area in the past are relatively well known (see table below). Historically, it appears that the most destructive source of origin is that of the subduction zone located beneath the Hellenic Arc (Crete in 365 and Rhodes in 1303). The eastern Mediterranean is still considered the most dangerous zone.
The most important Mediterranean tsunamis
|
Date |
Place of origin |
Remarks |
|
ca. - 1650 |
Santorini |
Tsunami generated by the eruption of the Thera volcano, with a wave estimated at 40 m. |
|
365 |
Crete |
Tsunami generated by an earthquake with a magnitude of around 8,5, with a wave estimated at 10 m. |
|
373 |
Helike |
Tsunami generated by an earthquake with a magnitude of around 7, with a wave estimated at 10 m. |
|
1303 |
Rhodes |
Tsunami generated by an earthquake with a magnitude of around 8. |
|
1365 |
Algiers |
Tsunami generated by an earthquake with a magnitude of around 7. |
|
1755 |
Lisbon |
Tsunami generated by an earthquake with a magnitude of around 8, with a wave estimated at 4 m. |
|
1908 |
Messina |
Tsunami generated by an earthquake with a magnitude of around 7, with a wave of 8 m. |
The northeast Atlantic seems less prone to tsunamis. However, the tsunami of 1 November 1755 off the coast of Lisbon was one of the most destructive ever recorded anywhere in the world, with 5-metre-high waves striking the harbour and killing 20,000 persons.
The West Indies , characterized by significant volcanic and seismic activity, also run the risk of tsunamis. The West Indies are affected by tsunamis generated in either the Caribbean or the Atlantic (subduction earthquakes or teletsunamis).
According to a 2001 study by Narcisse Zahibo and Efim Pelinovsky, around 24 tsunamis have been reported in the Lesser Antilles over the past 400 years. 5 ( * )
Finally, the Indian Ocean is not safe from tsunamis, either. While it is true that the area accounts for only 4% of recorded tsunamis, following the Sumatra catastrophe, the tsunami risk can no longer be ignored in this region. What's more, 3 large tsunamis have since been provoked by strong earthquakes on 28 March 2005, 17 July 2006 and 12 September 2007.
* 5 The Lesser Antilles are a string of small islands of volcanic or calcareous origin, which form an arc stretching from the Virgin Islands east of Puerto Rico to Grenada to the south.